Related

Only professionals or very handy, experienced homeowners should install windows. A poorly hung window can be very inefficient. Here are some tips:

Make sure the windows are squarely installed to prevent air gaps.

Spray Great Stuff or other foam insulation in the gaps between the wall and the window frame.

Caulk all the way around the inside and outside of each window.

An energy auditor can measure the leakage around windows. A blower door test will show if air is seeping in around the window frame. If the windows are well-sealed and the home is fairly airtight, be sure fans and ducts are working properly. Otherwise, you may seal in indoor air pollutants.

Window frames can make a major difference in overall home energy efficiency. Carefully consider the style, material, and installation before replacing windows.